The following relates generally to wireless communication and more specifically to hybrid automatic repeat request (HARQ) timing for reduced transmission time intervals (TTIs).
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems. A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may each be referred to as a user equipment (UE).
Wireless multiple-access technologies have been adopted in various telecommunication standards to provide a common protocol that enable different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is designed to improve spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards. LTE may use OFDMA on the downlink (DL), single-carrier frequency division multiple access (SC-FDMA) on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology.
In an LTE system, a UE may transmit HARQ feedback information to facilitate error correction and data transmission. HARQ processing procedures may, however, create delays between reception of downlink information and HARQ feedback transmission. These delays may result in increased latency and a decrease in overall system performance. Certain HARQ procedures also may not account for communications that use TTIs of different durations.